FYI I have made a tool that can backup / copy your account settings, subscriptions, and blocks to a new account: github.com/CMahaff/lasim
There are others out there as well if you look.
Obviously the loss of .ml communities would still be catastrophic to Lemmy, but at least your new account won’t start from ground-zero, and you can be less effected by downtime by having 2 accounts with the same subscriptions.